Process of producing nitrogen compounds and apparatus therefor



June 1 1926.

- E. s. MATTHEWS PROCESS OF PRODUCING NITROGEN COMPOUNDS AND APPARATUSTHEREFOR Original Filed August 2 19 5% $1 mtO'LMQ-txS MAQMAV;

Patented June 1, 1926.

UNITED STATES,

PATENT OFFICE.

EDWIN S. MATTHEWS, OF NEW YORK, N. Y.

Application filed August 29, 1917, Serial No. 188,736. Renewed October23, 1925.

My invention relates to new and useful improvements in process ofproducing nitrogen compounds and apparatus therefor, and its object isto provide a more etficient process for this purpose and to supply aneed in such processes as have been available heretofore.

More specifically, the object of this invention is to provide steps inthe process of lo producing nitrogen compounds by which nitrogen iseffectively oxidized and further whichwhile they are in the state ofoxides of nitrogen will prevent them after being formed fromdissociating until they have reached a condition of stability, and toprovide apparatus for carrying out these steps of the process.

In order that my invention may be thoroughly understood,.I will nowproceed to describe the same in the following specification, and theirpoint out the novel features thereof in appended claims.

Referring to the drawings:

Figure 1 is a diagrammatic elevation, partly in section, of an apparatuswhich is an embodiment of a part of my invention,

and illustrates a means for practicing my novel process.

Figure 2 is a diagrammatic plan view 80 partly in section, of the sameapparatus and certain additional parts.

Like characters of reference designate corresponding parts in both ofthe figures.

10 designates a casing which forms a chamber 11, lined with a high heatresistant material12, such for example, as alundum and around theoutside of which are a plurality of cooling pipes 13. 14 and 15 areelectrodes between which a series of electric arcs are formed,preferably by an alternating current. On opposite sides of theseelectrodes are the pole pieces 16 and 17 of an electro-magnet, theenergizing coil of which, designated by 18, is supplied from a directcurrent source of energy.

This electrical apparatus is described but briefly as it is well knownand in common use.

20 is a water jacketed nozzle through which dry air under pressure isblown through the electric are. 21 is a pipe from an air compressor 22.The suction pipe of the air compressor leads from a de-hydrator 23filled with quick lime or other suitable hygroscopic material. Water issupplie from a pump 24 through a pipe 25 to the.

water jacket of the nozzle from which it flows through a pipe connection26 into the pipe coils 13. 27 is a check valve in pipe 25 and 28 is thesupply pipe to the pump.

'30 is a casing which forms a pressure chamber in open communicationwith chamber 11 through which the gases pass after they emerge from thechamber 11. In this chamber is a spiral pipe coil 31, one end of whichis connectedto the discharge end of the cooling pipes 13 and the otherend of which designated by 32 is connected with a steam dome 33,. 34 isthe steam pipe from this dome.

35 is a lining of refractory material which covers the inside of thepipe coil 31. This lining is thicker at the end thereof which isadjacent to the chamber 11.

36 is another pipe coil.in the pressure chamber. This is supplied withwater from the pump 24 through a reducing valve 29 and a pipe 37. 38 isa discharge pipe from coil 36. I

At the end of the pressure chamber is a relief valve 39 set to open at.a pressure slightly less than that at which air is introduced intochamber 11' through nozzle 20.

40 is a duct leading from the pressure chamber 30 beyond the reliefvalve into the base of an absorbing receptacle 41'. 42 is another ductleading from the top of absorbing receptacle 41 into the base of asecond absorbing receptacle 43, and 44 is an exhaust pipe leading fromthe top of this receptacle 43.

Water is su plied from pump 24 through a reducing va ve 45 and a pipe 46into the s top of the first absorbing receptacle. From the bottom of thefirst receptacle it runs through a pipe 47 into the top of the secondreceptacle from the'bottom of which it runs out through a pipe. 48.

50 is .a steam motor, 51 its supply pipe, and 52 a valve therein. Itsexhaust pipe is designated by 53. The motor 50 is shown diagrammaticallyconnected to drive the compressor 22 and the pump 24 by belts 54 and 55respectively.

The operation is as follows: A fluctuating arc is produced between theelectrodes 14 and 15. The dry air passing through this arc is subjectedto its heat and its oxygen and nitrogen are united there y. During thisoperation the gases are m intained und der pressure and the structure ofthe apparatus is such as to maintain and retain the heat within thechamber, thus increasing the yield of oxides of nitrogen. By drying theair before its introduction into the chamber 11, the hydrogen containedin its moisture is removed, the presence of which is undesirable.

This heating of the gases may be accomplished in other of the well knownWays. The synthesized gases are at a very high temperature. IVithoutpressure these gases would in cooling pass through temperatures at whichthey are extremely unstable. But I have discovered that if pressure ismaintained upon them while they pass through these critical temperaturesof dissociation, they will not dissociate and may be reduced to lowertemperatures at which they are stable. Therefore, in my process thesehot gases are cooled below the critical temperature of dissociationbefore the pressure is released. The pipe coil 31 tends to cool thegases and the refractory lining 35 is provided to protect the coil. Theheat absorbed by the water is not wasted but is retained by dischargingthe pipe coil 31 into the steam dome 33 and leading the steam therefromthrough pipe 34 into the steam motor 50.

By the time the gases have reached pipe coil 36 their temperature hasbeen reduced to such an extent as to make it practicable to omit aprotective lining such as 35. Here the gas temperature is furtherreduced so that by the time the oxides of nitrogen reach the reliefvalve 39 they are no longer in their sensitive condition but are in acondition of stability.

The oxides of nitrogen are absorbed by the water passing through thereceptacle 41 in the usual manner, but I prefer to repeat this absorbingprocess in one or more receptacles such as 43 so that when the gases aredischarged through pipe 44: practically all of the oxides of nitrogenhave been removed and absorbed by the water so that the liquid passingout through pipe 18 is acidulated to a greater degree of concentrationthan is usual with former processes.

The principle of this invention is broad enough to cover its use withother gases than air.

I also contemplate for the purpose of obtaining a greater yield ofproduct, the introducti on of oxygen with the air.

I intend only such limitations as are imposed by the appended claims.

What I claim is:

1. synthesizing oxygen and nitrogen by heating'air under pressuremaintaining the pressure, absorbing heat from the product while stillunder pressure, and utilizing the absorbed heat for producing thepressure on the air and said products.

2. Synthesizing oxygen and nitrogen by compressing air, passing the airunder pressure through a heating medium maintaining the pressure, andpassing the air and its products through a heat absorbing passage whilestill under pressure, and utilizing the absorbed heat for compressingand circulating the air and said products and for applying cooling fluidto the heat absorbing passage.

3. An apparatus for forming nitrogen compounds comprising a heatingpressure chamber and a cooling pressure chamber in communicationtherewith, means for passing air and its synthesized components underpressure through said chambers, a water jacket for said cooling chamber,and means for passing water through said synthesized components.

4. An apparatus for forming oxides of nitrogen comprising a heatingpressure chamber and a cooling pressure chamber in communicationtherewith, means for passing air and its synthesized components underpressure through said chambers, a water jacket for said cooling chamber,means for forcing water into said water jacket, a motor for actuatingsaid circulating and forcing means, and means for utilizing the heatabsorbed the water acket in said motor.

5. An apparatus for forming nitrogen compounds comprising a heatingpressure chamber and a cooling pressure chamber in communicationthegewith, means for passing air and its synthesized components underpressure through said chambers, a water jacket for said cooling chamber,means for forcing water into said water jacket, means for passing waterthrough said synthesized components, a motor for actuating saidcirculating, forcing and passing means, and means for utilizing the heatabsorbed by the water jacket in said motor.

6. An apparatus for forming nitrogen compounds comprising a heatingpressure chamber and a cooling pressure chamber in comi unicationtherewith, means for passing air and its synthesized components underpressure through said chambers, and a water jacket for said coolingchamber arranged to reduce the temperature of said air and itssynthesized products while the pressure thereon is still maintained.

In witness whereof, I have hereunto set my hand this 28 day of August,1917.

EDIVIN S. MATTHEIVS.

